package com.lxp.common;


import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * @author lxp
 * @Motto 每天一行小代码，健康幸福学JAVA：
 * @create 2022-08-24 17:50
 * @Description: 文件上转和下次载
 */

@RestController
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        // 原始文件名
        String filename = file.getOriginalFilename();
        // 截取出文件的 后缀
        String suffix = filename.substring(filename.lastIndexOf("."));
        // 使用UUI重新生成文件名防止文件覆盖
        String newFilename = UUID.randomUUID().toString() + suffix;

        // 创建一个文件目录对象
        File dri = new File(basePath);
        if (!dri.exists()){
            dri.mkdir();
        }
        try {
            // 将文件输出到指定的位置
            file.transferTo(new File(basePath + newFilename));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(newFilename);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void downLoad(String name, HttpServletResponse response){
        try {
            // 读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));

            // 输出流，用于写入浏览器展示的图片
            ServletOutputStream outputStream = response.getOutputStream();
            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            // 关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}
